/* *
 *
 *  (c) 2010-2019 Highsoft AS
 *
 *  Author: Sebastian Domas
 *
 *  License: www.highcharts.com/license
 *
 *  !!!!!!! SOURCE GETS TRANSPILED BY TYPESCRIPT. EDIT TS FILE ONLY. !!!!!!!
 *
 * */
"use strict";
import H from "../parts/Globals.js";
import U from "../parts/Utilities.js";
var correctFloat = U.correctFloat,
  isNumber = U.isNumber;
import derivedSeriesMixin from "../mixins/derived-series.js";
var seriesType = H.seriesType,
  merge = H.merge;
/* ************************************************************************** *
 *  BELL CURVE                                                                *
 * ************************************************************************** */
/* eslint-disable valid-jsdoc */
/**
 * @private
 */
function mean(data) {
  var length = data.length,
    sum = data.reduce(function (sum, value) {
      return (sum += value);
    }, 0);
  return length > 0 && sum / length;
}
/**
 * @private
 */
function standardDeviation(data, average) {
  var len = data.length,
    sum;
  average = isNumber(average) ? average : mean(data);
  sum = data.reduce(function (sum, value) {
    var diff = value - average;
    return (sum += diff * diff);
  }, 0);
  return len > 1 && Math.sqrt(sum / (len - 1));
}
/**
 * @private
 */
function normalDensity(x, mean, standardDeviation) {
  var translation = x - mean;
  return (
    Math.exp(
      -(translation * translation) / (2 * standardDeviation * standardDeviation)
    ) /
    (standardDeviation * Math.sqrt(2 * Math.PI))
  );
}
/* eslint-enable valid-jsdoc */
/**
 * Bell curve class
 *
 * @private
 * @class
 * @name Highcharts.seriesTypes.bellcurve
 *
 * @augments Highcharts.Series
 */
seriesType(
  "bellcurve",
  "areaspline",
  /**
   * A bell curve is an areaspline series which represents the probability
   * density function of the normal distribution. It calculates mean and
   * standard deviation of the base series data and plots the curve according
   * to the calculated parameters.
   *
   * @sample {highcharts} highcharts/demo/bellcurve/
   *         Bell curve
   *
   * @extends      plotOptions.areaspline
   * @since        6.0.0
   * @product      highcharts
   * @excluding    boostThreshold, connectNulls, dragDrop, stacking,
   *               pointInterval, pointIntervalUnit
   * @requires     modules/bellcurve
   * @optionparent plotOptions.bellcurve
   */
  {
    /**
     * This option allows to define the length of the bell curve. A unit of
     * the length of the bell curve is standard deviation.
     *
     * @sample highcharts/plotoptions/bellcurve-intervals-pointsininterval
     *         Intervals and points in interval
     */
    intervals: 3,
    /**
     * Defines how many points should be plotted within 1 interval. See
     * `plotOptions.bellcurve.intervals`.
     *
     * @sample highcharts/plotoptions/bellcurve-intervals-pointsininterval
     *         Intervals and points in interval
     */
    pointsInInterval: 3,
    marker: {
      enabled: false,
    },
  },
  merge(derivedSeriesMixin, {
    setMean: function () {
      this.mean = correctFloat(mean(this.baseSeries.yData));
    },
    setStandardDeviation: function () {
      this.standardDeviation = correctFloat(
        standardDeviation(this.baseSeries.yData, this.mean)
      );
    },
    setDerivedData: function () {
      if (this.baseSeries.yData.length > 1) {
        this.setMean();
        this.setStandardDeviation();
        this.setData(
          this.derivedData(this.mean, this.standardDeviation),
          false
        );
      }
      return void 0;
    },
    derivedData: function (mean, standardDeviation) {
      var intervals = this.options.intervals,
        pointsInInterval = this.options.pointsInInterval,
        x = mean - intervals * standardDeviation,
        stop = intervals * pointsInInterval * 2 + 1,
        increment = standardDeviation / pointsInInterval,
        data = [],
        i;
      for (i = 0; i < stop; i++) {
        data.push([x, normalDensity(x, mean, standardDeviation)]);
        x += increment;
      }
      return data;
    },
  })
);
/**
 * A `bellcurve` series. If the [type](#series.bellcurve.type) option is not
 * specified, it is inherited from [chart.type](#chart.type).
 *
 * For options that apply to multiple series, it is recommended to add
 * them to the [plotOptions.series](#plotOptions.series) options structure.
 * To apply to all series of this specific type, apply it to
 * [plotOptions.bellcurve](#plotOptions.bellcurve).
 *
 * @extends   series,plotOptions.bellcurve
 * @since     6.0.0
 * @product   highcharts
 * @excluding dataParser, dataURL, data
 * @requires  modules/bellcurve
 * @apioption series.bellcurve
 */
/**
 * An integer identifying the index to use for the base series, or a string
 * representing the id of the series.
 *
 * @type      {number|string}
 * @apioption series.bellcurve.baseSeries
 */
(""); // adds doclets above to transpiled file
